Method and apparatus for multicast mobility

ABSTRACT

A method and an apparatus for a proxy mobile Internet protocol (PMIP) supporting a dedicated multicast local mobility anchor (LMA) and mobile access gateway (MAG) is provided. The LMA assigns an Internet Protocol (IP) address to a wireless transmit receive unit (WTRU) that processes the IP address and sends a router solicitation message to a serving MAG. A WTRU is disclosed to receive a first IP address that is for unicast service and a second IP address that is for multicast services. Generally, the method and apparatus proposes architecture, interfaces, and procedures to enable multicast mobility using Proxy Mobile IP. More specifically operations of aggregated PMIP tunnels for multicast services are described. Multicast mobility is enabled when mobile nodes move from one MAG to another MAG, intra-LMA, and inter-LMA. And, Multicast mobility is enabled between bidirectional network and downlink only multicast network in a hybrid network.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 61/243,810 filed on Sep. 18, 2009; and U.S. Provisional ApplicationSer. No. 61/315,459 filed on Mar. 19, 2010, all of which are herebyincorporated by reference as if fully set forth herein.

FIELD OF INVENTION

This application is related to mobile communications.

BACKGROUND

Existing downlink only multicast networks, such as digital videobroadcasting (DVB), media forward link only (MediaFLO), and the like,have significant limitations. Network coverage is usually regional andtherefore a wireless transmit receive unit (WTRU), or a mobile node,loses access to the multicast service when the WTRU moves beyond acoverage area. While a WTRU may be able to re-subscribe and receive theservice over a bi-directional communication network, all of the sessioncontinuity is lost.

In existing bi-directional mobile communication networks (e.g., thirdgeneration partnership program (3GPP), multimedia broadcast multicastservices (MBMS), and the like), mobility is only addressed within eachrespective standard. Inter-technology mobility also does not support themulticast services.

In existing hybrid networks such as overlaid downlink only andbi-directional networks, mobility may be supported at the applicationlevel with the open mobile alliance digital mobile broadcast enabler(OMA BCAST). These types of hybrid networks typically utilize abreak-before-make service, which often results in long serviceinterruptions.

FIG. 1 illustrates the architecture of a proxy mobile internet protocol(IP)v6 (PMIPv6) domain. The PMIP has been introduced for network-basedmobility management. The core functional entities in the network-basedlocalized mobility management (NETLMM) infrastructure are a localmobility anchor (LMA) and a mobile access gateway (MAG) 106. There maybemultiple local mobility anchors (LMAs) 102 in a PMIPv6 domain eachserving a different group of WTRUs. The LMA 102 is responsible formaintaining the reachability state of the WTRU 108 and is thetopological anchor point for WTRU's 108 home network prefixes (HNP). TheMAG 106 is the entity that performs the mobility management on behalf ofthe WTRU 108, and it resides on the access link where the WTRU 108 isanchored. The MAG 106 is responsible for detecting the movement of theWTRU 108 to and from the access link and for initiating bindingregistration to the WTRU's 108 LMA 102. The WTRU 108 may be an IPv4-onlynode, IPv6-only node, or a dual-stack node.

The WTRU's home network prefix (WTRU-HNP) 110 is a prefix assigned tothe link between the WTRU 108 and the MAG 106. More than one prefix maybe assigned to the link between the WTRU 108 and the MAG 106. The proxycare-of address (Proxy-CoA) 112 is the global address configured on theegress interface of the MAG 106 and is the transport endpoint of thetunnel between the LMA 102 and the MAG 106. The LMA address (LMAA) 114is the global address that is configured on the interface of the LMA 102and is the transport endpoint of the bi-directional tunnel establishedbetween the LMA 102 and the MAG 106. The IPv4/IPv6 network 104 refers tothe network where the mobility management of a WTRU 108 is handled usingPMIPv4/PMIPv6. The PMIPv4/PMIPv6 104 includes LMAs 102 and MAGs 106between which security associates may be set up and authorization forsending proxy binding updates on behalf of the WTRUs 108 may be ensured.

These types of existing Layer 3 mobility protocols (e.g., PMIP, sessioninitiation protocol (SIP), and the like) are designed for unicasttraffic. They lack support for multicast services. Further, existingmulticast protocols such as internet group management protocol (IGMP) ormulticast listener discovery (MLD) need to be enhanced to reduce thelatency inherent in resuming multicast services after handover.

A method and an apparatus to enable enhanced mobility for the existingand evolving multicast services, such as multicast multimedia (e.g.,mobile TV, radio, presence, micro-blogging, file sharing, podcast,social networking, and the like) is desired.

SUMMARY

A method and an apparatus for a PMIP supporting a dedicated multicastLMA is provided, including, one option for a first LMA assigning an IPaddress to a WTRU subscribed for both unicast services and multicastservices, a WTRU processing received IP address and sending a routersolicitation message to a serving MAG, and the serving MAG triggering aproxy binding update (PBU) message to the first LMA.

In another option, a method implemented in a WTRU including a receiverconfigured to receive two sets of IP addresses, wherein one set of IPaddresses is for unicast services and another set of IP addresses is formulticast services, a processor configured to use the one set of IPaddresses for unicast services and the other set of IP addresses formulticast services, and a transmitter configured to transmit a routersolicitation message to a serving MAG triggering two PBU messages, onefrom the serving MAG to the unicast LMA, and one from the serving MAG tothe multicast LMA.

Generally, the method and apparatus proposed includes an architecture,interface, and procedures to enable multicast mobility using ProxyMobile IP. More specifically, several solutions are described in thefollowing areas. Operations of aggregated PMIP tunnels for multicastservices are described. A new architecture to have a dedicated LMA asmulticast anchor, and a new PMIP procedure on IP address assignment, MAGfunctionalities, and WTRU's profile are introduced. Multicast mobilityis enabled when mobile nodes move from one MAG to another MAG,intra-LMA, and inter-LMA. MLD/IGMP enhancements to reduce latency inresuming multicast services are described. And, multicast mobility isenabled between bidirectional network and downlink only multicastnetwork in a hybrid network.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1 illustrates an architecture of proxy mobile IPv6 domain;

FIG. 2A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented;

FIG. 2B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 2A;

FIG. 2C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 2A;

FIG. 2D is an example block diagram comprising components of a multicastmobility network

FIG. 3 shows an architecture of a PMIP multicast tunnel aggregation;

FIG. 4 illustrates a dedicated multicast LMA architecture;

FIGS. 5A and 5B shows flow diagram of the dedicated multicast servicesas illustrated in FIG. 4;

FIG. 6 shows the architecture of PMIP intra-LMA multicast mobilityenablement;

FIGS. 7A and 7B shows a communication between the entities of thenetwork for an intra-LMA multicast mobility as illustrated in FIG. 6;

FIG. 8 shows the architecture of PMIP inter-LMA multicast mobilityenablement; and

FIG. 9 shows the architecture of multicast mobility in a hybrid network.

DETAILED DESCRIPTION

When referred to hereafter, the terminology “wireless transmit/receiveunit (WTRU)” includes but is not limited to a user equipment (UE), amobile station, a fixed or mobile subscriber unit, a pager, a cellulartelephone, a personal digital assistant (PDA), a computer, a mobile node(MN), or any other type of device capable of operating in a wirelessenvironment. When referred to hereafter, the terminology “base station”includes but is not limited to a Node-B, a site controller, an accesspoint (AP), an evolved Node-B (eNB), a router, a gateway, or any othertype of interfacing device capable of operating in a wirelessenvironment.

Method and apparatus disclosed herewith enhances layer 3 mobility forPMIP and may be applied to different access technologies regardless oflink layer or physical layer. Both unicast and multicast can be used fortransmissions. However, using multicast at lower layers, together withthe L3 mulitcast mobility support may enhance the overall systemefficiency. Embodiments presented herewith enable the advantages ofmulticast transmissions at lower layers. For example, MBMS can be usedin long term evolution (LTE) and physical multicast channel (PMCH),multicast control channel (MCCH), and multicast traffic channel (MTCH)can be used to carry the multicast data.

FIG. 2A is a diagram of an example communications system 200 in whichone or more disclosed embodiments may be implemented. The communicationssystem 200 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 200 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems200 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 2A, the communications system 200 may include wirelesstransmit/receive units (WTRUs) 108 a, 108 b, 108 c, 108 d, a radioaccess network (RAN) 204, a core network 206, a public switchedtelephone network (PSTN) 208, the Internet 210, and other networks 212,though it will be appreciated that the disclosed embodiments contemplateany number of WTRUs, base stations, networks, and/or network elements.Each of the WTRUs 108 a, 108 b, 108 c, 108 d may be any type of deviceconfigured to operate and/or communicate in a wireless environment. Byway of example, the WTRUs 108 a, 108 b, 108 c, 108 d may be configuredto transmit and/or receive wireless signals and may include userequipment (UE), a mobile station, a mobile node, a fixed or mobilesubscriber unit, a pager, a cellular telephone, a personal digitalassistant (PDA), a smartphone, a laptop, a netbook, a personal computer,a wireless sensor, consumer electronics, and the like.

The communications systems 200 may also include a base station 214 a anda base station 214 b. Each of the base stations 214 a, 214 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 108 a, 108 b, 108 c, 108 d to facilitate access to one or morecommunication networks, such as the core network 206, the Internet 210,and/or the networks 212. By way of example, the base stations 214 a, 214b may be a base transceiver station (BTS), a Node-B, an eNode B, a HomeNode B, a Home eNode B, a site controller, an access point (AP), awireless router, and the like. While the base stations 214 a, 214 b areeach depicted as a single element, it will be appreciated that the basestations 214 a, 214 b may include any number of interconnected basestations and/or network elements.

The base station 214 a may be part of the RAN 204, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 214 a and/or the base station 214 b may beconfigured to transmit and/or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown). The cell may further be divided into cell sectors. For example,the cell associated with the base station 214 a may be divided intothree sectors. Thus, in one embodiment, the base station 214 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 214 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 214 a, 214 b may communicate with one or more of theWTRUs 108 a, 108 b, 108 c, 108 d over an air interface 216, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, etc.). Theair interface 216 may be established using any suitable radio accesstechnology (RAT).

More specifically, as noted above, the communications system 200 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 214 a in the RAN 204 and the WTRUs 108 a, 108b, 108 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 216 using wideband CDMA (WCDMA). WCDMAmay include communication protocols such as High-Speed Packet Access(HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed DownlinkPacket Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

In another embodiment, the base station 214 a and the WTRUs 108 a, 108b, 108 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface216 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 214 a and the WTRUs 108 a, 108 b,108 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 214 b in FIG. 2A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 214 b and the WTRUs 108 c, 108 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 214 band the WTRUs 108 c, 108 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 214 b and the WTRUs 108 c, 108 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 2A,the base station 214 b may have a direct connection to the Internet 210.Thus, the base station 214 b may not be required to access the Internet210 via the core network 206.

The RAN 204 may be in communication with the core network 206, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 108 a, 108 b, 108 c, 108 d. For example, the core network 206may provide call control, billing services, mobile location-basedservices, pre-paid calling, Internet connectivity, video distribution,etc., and/or perform high-level security functions, such as userauthentication. Although not shown in FIG. 2A, it will be appreciatedthat the RAN 204 and/or the core network 206 may be in direct orindirect communication with other RANs that employ the same RAT as theRAN 204 or a different RAT. For example, in addition to being connectedto the RAN 204, which may be utilizing an E-UTRA radio technology, thecore network 206 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 206 may also serve as a gateway for the WTRUs 108 a,108 b, 108 c, 108 d to access the PSTN 208, the Internet 210, and/orother networks 212. The PSTN 208 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet210 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) andthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 212 may include wired or wireless communications networks ownedand/or operated by other service providers. For example, the networks212 may include another core network connected to one or more RANs,which may employ the same RAT as the RAN 204 or a different RAT.

Some or all of the WTRUs 108 a, 108 b, 108 c, 108 d in thecommunications system 200 may include multi-mode capabilities, i.e., theWTRUs 108 a, 108 b, 108 c, 108 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 108 c shown in FIG. 2A may be configured tocommunicate with the base station 214 a, which may employ acellular-based radio technology, and with the base station 214 b, whichmay employ an IEEE 802 radio technology.

FIG. 2B is a system diagram of an example WTRU 108. As shown in FIG. 2B,the WTRU 108 may include a processor 218, a transceiver 220, atransmit/receive element 222, a speaker/microphone 224, a keypad 226, adisplay/touchpad 228, non-removable memory 206, removable memory 232, apower source 234, a global positioning system (GPS) chipset 236, andother peripherals 238. It will be appreciated that the WTRU 108 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment.

The processor 218 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 218 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 108 to operate in a wirelessenvironment. The processor 218 may be coupled to the transceiver 220,which may be coupled to the transmit/receive element 222. While FIG. 2Bdepicts the processor 218 and the transceiver 220 as separatecomponents, it will be appreciated that the processor 218 and thetransceiver 220 may be integrated together in an electronic package orchip.

The transmit/receive element 222 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 214a) over the air interface 216. For example, in one embodiment, thetransmit/receive element 222 may be an antenna configured to transmitand/or receive RF signals. In another embodiment, the transmit/receiveelement 222 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 222 may be configured totransmit and receive both RF and light signals. It will be appreciatedthat the transmit/receive element 222 may be configured to transmitand/or receive any combination of wireless signals.

In addition, although the transmit/receive element 222 is depicted inFIG. 2B as a single element, the WTRU 108 may include any number oftransmit/receive elements 222. More specifically, the WTRU 108 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 108 mayinclude two or more transmit/receive elements 222 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 216.

The transceiver 220 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 222 and to demodulatethe signals that are received by the transmit/receive element 222. Asnoted above, the WTRU 108 may have multi-mode capabilities. Thus, thetransceiver 220 may include multiple transceivers for enabling the WTRU108 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 218 of the WTRU 108 may be coupled to, and may receiveuser input data from, the speaker/microphone 224, the keypad 226, and/orthe display/touchpad 228 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor218 may also output user data to the speaker/microphone 224, the keypad226, and/or the display/touchpad 228. In addition, the processor 218 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 206 and/or the removable memory 232.The non-removable memory 206 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 232 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 218 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 108, such as on a server or a home computer (notshown).

The processor 218 may receive power from the power source 234, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 108. The power source 234 may be any suitabledevice for powering the WTRU 108. For example, the power source 234 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 218 may also be coupled to the GPS chipset 236, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 108. In additionto, or in lieu of, the information from the GPS chipset 236, the WTRU108 may receive location information over the air interface 216 from abase station (e.g., base stations 214 a, 214 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 108 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 218 may further be coupled to other peripherals 238, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 238 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 2C is a system diagram of the RAN 204 and the core network 206according to an embodiment. The RAN 204 may be an access service network(ASN) that employs IEEE 802.16 radio technology to communicate with theWTRUs 108 a, 108 b, 108 c over the air interface 216. As will be furtherdiscussed below, the communication links between the differentfunctional entities of the WTRUs 108 a, 108 b, 108 c, the RAN 204, andthe core network 206 may be defined as reference points.

As shown in FIG. 2C, the RAN 204 may include base stations 240 a, 240 b,240 c, and an ASN gateway 242, though it will be appreciated that theRAN 204 may include any number of base stations and ASN gateways whileremaining consistent with an embodiment. The base stations 240 a, 240 b,240 c may each be associated with a particular cell (not shown) in theRAN 204 and may each include one or more transceivers for communicatingwith the WTRUs 108 a, 108 b, 108 c over the air interface 216. In oneembodiment, the base stations 240 a, 240 b, 240 c may implement MIMOtechnology. Thus, the base station 240 a, for example, may use multipleantennas to transmit wireless signals to, and receive wireless signalsfrom, the WTRU 108 a. The base stations 240 a, 240 b, 240 c may alsoprovide mobility management functions, such as handoff triggering,tunnel establishment, radio resource management, traffic classification,quality of service (QoS) policy enforcement, and the like. The ASNgateway 242 may serve as a traffic aggregation point and may beresponsible for paging, caching of subscriber profiles, routing to thecore network 206, and the like.

The air interface 216 between the WTRUs 108 a, 108 b, 108 c and the RAN204 may be defined as an R1 reference point that implements the IEEE802.16 specification. In addition, each of the WTRUs 108 a, 108 b, 108 cmay establish a logical interface (not shown) with the core network 206.The logical interface between the WTRUs 108 a, 108 b, 108 c and the corenetwork 206 may be defined as an R2 reference point, which may be usedfor authentication, authorization, IP host configuration management,and/or mobility management.

The communication link between each of the base stations 240 a, 240 b,240 c may be defined as an R8 reference point that includes protocolsfor facilitating WTRU handovers and the transfer of data between basestations. The communication link between the base stations 240 a, 240 b,240 c and the ASN gateway 242 may be defined as an R6 reference point.The R6 reference point may include protocols for facilitating mobilitymanagement based on mobility events associated with each of the WTRUs108 a, 108 b, 108 c.

As shown in FIG. 2C, the RAN 204 may be connected to the core network206. The communication link between the RAN 204 and the core network 206may defined as an R3 reference point that includes protocols forfacilitating data transfer and mobility management capabilities, forexample. The core network 206 may include a mobile IP home agent(MIP-HA) 244, an authentication, authorization, accounting (AAA) server246, and a gateway 248. The MIP-HA 244 may be proxy MIP-HA (PMIP-HA).While each of the foregoing elements are depicted as part of the corenetwork 206, it will be appreciated that any one of these elements maybe owned and/or operated by an entity other than the core networkoperator.

The PMIP-HA 244 may be responsible for IP address management, and mayenable the WTRUs 108 a, 108 b, 108 c to roam between different ASNsand/or different core networks. The PMIP-HA 244 may provide the WTRUs108 a, 108 b, 108 c with access to packet-switched networks, such as theInternet 210, to facilitate communications between the WTRUs 108 a, 108b, 108 c and IP-enabled devices. The AAA server 246 may be responsiblefor user authentication and for supporting user services. The gateway248 may facilitate interworking with other networks. For example, thegateway 248 may provide the WTRUs 108 a, 108 b, 108 c with access tocircuit-switched networks, such as the PSTN 208, to facilitatecommunications between the WTRUs 108 a, 108 b, 108 c and traditionalland-line communications devices. In addition, the gateway 248 mayprovide the WTRUs 108 a, 108 b, 108 c with access to the networks 212,which may include other wired or wireless networks that are owned and/oroperated by other service providers.

Although not shown in FIG. 2C, it will be appreciated that the RAN 204may be connected to other ASNs and the core network 206 may be connectedto other core networks. The communication link between the RAN 204 theother ASNs may be defined as an R4 reference point, which may includeprotocols for coordinating the mobility of the WTRUs 108 a, 108 b, 108 cbetween the RAN 204 and the other ASNs. The communication link betweenthe core network 206 and the other core networks may be defined as an R5reference, which may include protocols for facilitating interworkingbetween home core networks and visited core networks.

FIG. 2D is an exemplary block diagram 250 comprising the WTRU 108, theeNB 240, and the Mobility Management Entity (MME)/Serving GateWay (S-GW)142. As shown in FIG. 2D, the WTRU 108, the eNB 240 and the MME/S-GW 142are configured to perform a method for multicast mobility.

In addition to the components that may be found in a typical WTRU, theWTRU 108 includes a processor 316 with an optional linked memory 322, atleast one transceiver 314, an optional battery 320, and an antenna 318.The processor 316 is configured to perform a method for multicastmobility.

The transceiver 314 is in communication with the processor 316 and theantenna 318 to facilitate the transmission and reception of wirelesscommunications. In case a battery 320 is used in the WTRU 108, it powersthe transceiver 314 and the processor 316.

In addition to the components that may be found in a typical eNB, theeNB 240 includes a processor 317 with an optional linked memory 315,transceivers 319, and antennas 321. The processor 317 is configured toperform a method for multicast mobility.

The transceivers 319 are in communication with the processor 317 andantennas 321 to facilitate the transmission and reception of wirelesscommunications. The eNB 240 is connected to the Mobility ManagementEntity/Serving GateWay (MME/S-GW) 142 which includes a processor 333with an optional linked memory 334.

Referring to FIG. 3, PMIP tunnels may be aggregated for the multicastWTRUs, for example, the multicast group one 340 and multicast group two350. If using the exsiting proxy binding update (PBU) message, a newvariable-length of multicast options field (i.e., a portion or asegment) may be added to the existing proxy binding update (PBU)message. The PBU is a request message sent by the MAG 380 to a WTRU'srespective LMA for establishing a binding between the WTRU's HNPassigned to a predefined interface of a WTRU 340, 350, or 360 and itscurrent CoA (i.e., proxy-CoA). The WTRU's respective LMA may beconnected either to the unicast services 310 or the multicast services320. The multicast options field may contain a multicast CoA. A specificmulticast CoA is associated with the aggregated multicast tunnel 334 or332 ending at the MAG 380. Alternatively, a multicast flag may be addedin the PBU message. Alternatively, a new message can be used to signalmulticast information.

The multicast aggregated tunnels 332 and 334 may be pre-configured. Forexample, they may pre-exist between the LMA (Home Agent) 370 and the MAG380, even before any WTRUs 340, 350, or 360 subscribe to the multicastservices. The LMA 370 and the MAG 380 may exchange informationindicating that they both support multicast services using the messagesdescribed above. Multicast WTRUs 340 and 350 are added to the tunnel atthe time they are attached to the mobile network 330.

Alternatively, multicast aggregated tunnels 332 and 334 may be dynamic.Multicast aggregated tunnels do not exist before any multicast servicesare required. When multiple WTRUs 360 establish unicast tunnels 336 forthe multicast services, the LMA 370 and the MAG 380 may combine theseunicast tunnels 336 into an aggregated multicast tunnel, 332 or 334.

A WTRU may indicate a request for the multicast services to a MAG inseveral ways. The WTRU may use existing MLD/IGMP messages to indicate amulticast request to a MAG. Or, the WTRU may include multicastinformation in a router solicitation message.

Both, the LMA 370 and the MAG 380 may initiate the establishment of theaggregated tunnels for the multicast services. For initiation of tunnelaggregation from the MAG 380 to the LMA 370, a PBU message may be usedto initiate the process by adding a flag in the multicast options field,or a new message may be used. Multicast information may be stored ateither the LMA 370, or MAG 380, or both. Such multicast relatedinformation can be: multicast channels, the WTRUs subscribed to eachmulticast service, and each WTRU's respective network attachment.

A multicast tunnel may be unidirectional for downlink only traffic, orbi-directional (i.e., uplink and downlink communication). Controlinformation, such as the MLD/IGMP messages, may be sent over unicasttunnels or over aggregated multicast tunnels. For multicast and unicastservices, aggregated multicast and unicast tunnels may co-exist betweenthe LMA 370 and the MAG 380. A WTRU 360 with a unicast tunnel may alsobe associated with a multicast CoA. For example, a WTRU may have unicasttunnels 336 and aggregated multicast tunnels 332, 334.

Further, one or multiple multicast tunnels may exist. Such options mayinclude one multicast tunnel with one multicast CoA to serve allmulticast services, multiple multicast tunnels providing to separatedifferent multicast services, or a combination. The MAG 380 may indicatewhether multicast service is supported and available in a routeradvertisement message.

FIG. 4 illustrates a dedicated multicast LMA architecture 400. In thisembodiment, there is one LMA 470 dedicated for unicast services 410 andone LMA 480 dedicated for multicast services 420. Multiple LMAs 470 and480 may be used for each type of service, depending on the deployment ofthe respective network.

A WTRU 460 may have multiple interfaces. Thus, the WTRU 460 mayestablish a unicast tunnel 432, 436 with the unicast LMA 470, and amulticast tunnel 434, 438 with the multicast LMA 480, respectively inparallel. A WTRU 460 may have more than one home agent (HA). In thisarchitecture, the division of LMAs is based on a particular servicerequired.

In FIG. 4, a WTRU 460 moves from the p-MAG 440 to the n-MAG 450.Referring to FIG. 5A and FIG. 5B, additional details for the multicastservices are described. In this example, at least two methods aredescribed, one in FIG. 5A and another in FIG. 5B, where the IP addressassignment is used to support multicast services.

As seen in FIG. 5A, one set of IP addresses is assigned 510 from the LMAHA for unicast 470 to the WTRU 460. The IP addresses are used by theWTRU 460 for both unicast services 410 and multicast services 420. TheWTRU 460 transmits the router solicitation message 520 to the servingMAG, which triggers a PBU message from the serving MAG to the unicastLMA 470.

As seen in FIG. 5B, two sets of IP addresses are assigned 525 to theWTRU 460. One set of IP addresses is assigned from the unicast LMA HA470 for unicast 410 and a different set of IP addresses from themulticast LMA HA 480 for multicast 420. The WTRU 460 transmits therouter solicitation message 530 to the serving MAG, which will triggertwo PBU messages, one from the serving MAG to the unicast LMA 470 andanother to the multicast LMA 480.

In a case where the WTRU 460 does not require unicast services, the WTRU460 receives the IP addresses from the multicast LMA 480 for multicastservices 420 through a single PBU message from the serving MAG to themulticast LMA 480.

A binding update list maintained by a MAG is updated to have entries fora binding of the WTRU with both the unicast LMA 470 for unicast trafficand the multicast LMA 480 for multicast traffic.

The multicast traffic and unicast traffic forwarding may be handled bythe MAG by discriminating between the unicast and multicast trafficreceived related to a specific WTRU. The MAG may be able to discriminateby looking at source or destination addresses. The MAG may forward thetraffic on the correct interface.

For example, in FIG. 5A, when there is uplink traffic (i.e., from theWTRU 460 to the serving MAG), the serving MAG is able to determine if itshould be forwarded to the unicast LMA 470 for unicast traffic or themulticast LMA 480 for multicast control signaling. For the downlinktraffic, since there is only one interface at the WTRU 460, the servingMAG only needs to have a mapping of the tunnels for unicast tunnel andmulticast tunnel to the WTRU 460.

As another example in FIG. 5B, when different IP addresses are used forunicast services 410 and multicast services 420, the serving MAG needsto map the tunnels with the interfaces of the WTRU 460, in a mannersimilar to what it does in the PMIP multihoming case. PMIP allows mobilenodes to connect to a Proxy Mobile IPv6 domain through multipleinterfaces for simultaneous access. When a mobile node connects to aProxy Mobile IPv6 domain through multiple interfaces for simultaneousaccess, the local mobility anchor allocates a mobility session for eachof the attached interfaces. Each mobility session is managed under aseparate Binding Cache entry and with its own lifetime. When there existonly multicast services, the serving MAG maps the multicast tunnel withthe WTRU 460, in a manner similar to the unicast traffic.

The policy profile of the WTRU 460 stored in the policy server may beupdated by storing the IPv6 addresses of the LMA for unicast LMA 470 andLMA for multicast LMA 480. With the use of this information, the servingMAG of the WTRU 460 is able to obtain the multicast LMA addresses.

Alternatively, the MAG may maintain a multicast policy profile, whichmay map one or many LMA addresses to certain multicast groups, multicastoptions, or the link. A MAG may be able to attach to multiple LMAs. Forexample, a MAG may have a mandatory connection to the unicast LMA, andoptionally connect to the multicast LMA if the IP address assignment asdescribed in FIG. 5A is used. In this case, the connection to theunicast LMA 470 is mandatory, because that is where the IP address ofthe WTRU is assigned. A MAG may optionally have a connection to eitherthe unicast LMA 470 or the multicast LMA 480 if the IP addressassignment as described in FIG. 5B is used. In this example, the IPaddresses of the WTRU 460 may be assigned from either of the LMAsdepending on the type of services (either unicast or multicast)required.

FIG. 6 shows the architecture of PMIP intra-LMA multicast mobilityenablement 600. The embodiment shown in FIG. 6 is substantially the sameas that shown in FIG. 3, except that in this embodiment all or some ofthe WTRUs 630 move from a previously attached MAG (p-MAG) 610 to a newlyattached MAG (n-MAG) 620. An imminent handover (HO) trigger may comefrom the WTRU or the network, as a result of lower layer signaling, forexample, degraded signal strength, increased packet loss, and the like.One example of the lower layer signaling is a link going down message in802.21.

FIGS. 7A and 7B show a communication path for the PMIP intra-LMAmulticast mobility 700 and 750, respectively. As seen in FIG. 7A, theLMA 650 sends multicast packets 710 to the p-MAG 610. The p-MAG 610sends multicast packets 712 to the WTRU 630. The WTRU 630 informs thep-MAG 610 of imminent HO 714. The p-MAG 610 informs the n-MAG 620 of themulticast HO via a new interface, IF1, 716 between the p-MAG 610 and then-MAG 620. Alternatively, the imminent HO trigger and IF1 interface alsoapply to unicast services. The n-MAG 620 sends a PBU message to the LMA650 to establish an aggregated tunnel 718. The multicast options with amulticast CoA are provided to the LMA 650 by the n-MAG 620. The LMA 650sends multicast packets to the n-MAG 620, prior to actual HO 720. TheWTRU 630 which is associated to the pre-established aggregated tunnelmoves to the n-MAG 620, and receives multicast packets from theaggregated tunnel 722. On a condition that the aggregated tunnel betweenthe LMA and the p-MAG is not needed, the aggregated tunnel may beremoved.

Referring to FIG. 7B, the LMA 650 sends multicast packets 752 to thep-MAG 610. The p-MAG 610 sends multicast packets 754 to the WTRU 630.The WTRU 630 informs the p-MAG 610 of the imminent HO 756. The p-MAG 610passes the HO imminent information 758 to the LMA 650. The LMA 650initiates establishment of an aggregated multicast tunnel 760 betweenthe LMA 650 and the n-MAG 620. The LMA sends a Proxy Mobile IP messageto the n-MAG to establish the new multicast tunnel 762. On a conditionthat the LMA is aware of the received imminent HO, the LMA 650 mayinitiate the establishment of an aggregated multicast tunnel 762 betweenthe LMA 650 and the n-MAG 620. The LMA 650 sends multicast packets tothe n-MAG 620, prior to actual HO 764. The WTRU 630 which is associatedto the pre-established aggregated tunnel moves to the n-MAG 620, andreceives multicast packets from the aggregated tunnel 766. On acondition that the aggregated tunnel between the LMA 650 and the p-MAG610 is not needed, the aggregated tunnel may be removed.

Alternatively, the imminent HO trigger may come from the network. Thetrigger may be a result of the network load balancing or for amaintenance purpose (e.g., the p-MAG is going to be shutdown). Thenetwork trigger may come to the LMA 650 or the p-MAG 610. On a conditionthat the p-MAG 610 is aware of the received imminent HO, the p-MAG 610may inform the LMA 650 of the HO directly, or inform the n-MAG 620 ofthe HO. This embodiment proceeds similarly to the embodiment aboverelated to FIGS. 7A and 7B, where handover is triggered by a WTRU.

Alternatively, after the establishment of the aggregated tunnel 762,multicast traffic is sent from the LMA 650 to the n-MAG 620. The n-MAG620 may send a PBU message to the LMA 650 after the WTRU 630 is detectedon the network. However, this may cause a longer delay compared to themethod mentioned above where the tunnel is first pre-established andthen multicasting is started.

In another alternative embodiment, a multicast group ‘join’ message istransmitted on the targeted network before a HO. The multicastinformation obtained by the n-MAG 620 prior to the actual HO, asdescribed above in FIGS. 7A and 7B, may facilitate n-MAG 620'senablement of multicast services before the attachment of the WTRU. Themulticast information obtained by the n-access router (n-AR), on acondition that the PMIP is not used, prior to the actual HO mayfacilitate n-AR enablement of the multicast services before theattachment of the WTRU.

In another alternative, a mobility management entity in the network isinformed of the imminent HO. The mobility management entity joins themulticast group listened to by the WTRU with the appropriate multicastrouter on the targeted network before triggering the HO.

Another alternative utilizes a fast triggering multicast group ‘join’message after Layer 3 HO. The mobility management entity, that controlsthe HO triggers the sending of a MLD/IGMP report to join the multicastgroup as soon as the HO is complete. This is done immediately, insteadof waiting for a query from the multicast router, and thus reducing thedelay before resuming the multicast services.

These embodiments may be used independently or jointly. For example,when they are used together, and the multicast group ‘join’ prior to HOdid not work, the fast triggering multicast group ‘join’ message afterHO may succeed in reducing the service delay.

FIG. 8 shows the architecture of PMIP inter-LMA multicast mobilityenablement 800. In this embodiment, the WTRUs 730 move from the p-MAG710 to the n-MAG 720. The p-MAG 710 and the n-MAG 720 belong todifferent LMAs, LMA 750 and LMA 760, respectively. Each LMA 750 and LMA760 may provide both unicast and multicast services. The methoddescribed in FIG. 6 for a single LMA multicast mobility is used inconjunction with additional interfaces to inform the target LMA 750 and760 to enable the required multicast services. The interface IF1 is usedfor multicast information exchange between the source and target MAGs,710 and 720. The interface IF2 is used for multicast informationexchange between the source and the target LMAs, 750 and 760. Theinterface IF3 is used for multicast information exchange between thesource MAG 710 and the target LMA 760. The interface IF4 is used formulticast information exchange between the source LMA 750 and the targetMAG 720. These interfaces are alternatives and may not be available atthe same time.

FIG. 9 extends a single type of network to a hybrid network for themobility 900. Referring to FIG. 9, a bi-directional mobile networkcombined with a downlink only multicast network 925 is shown. In such ahybrid network, HO may occur from the bi-directional network to adownlink only multicast network 925. In a first example, the HO is WTRU930 triggered, using interface IF3 and interface IF4. A mobility cliententity 932 in the WTRU 930 detects the imminent HO. The mobility client932 informs a multicast service entity 934 (e.g., OMA BCASTfunctionalities 934 in the WTRU) via the interface IF3. The multicastservice entity 934 informs its counter part 916 in the network 915(e.g., OMA service adaptation/distribution functionalities in thenetwork) of the imminent HO via the interface IF4, and requires servicedistribution in the downlink only network 925. The interface IF4 may bea new interface, or it may be an existing OMA BCAST-5 interface withenhancement to support the HO information.

In another example, the HO is WTRU 930 triggered, using interfaces IF1and IF2. A mobility client entity 932 in the WTRU 930 detects theimminent HO. The mobility client entity 932 informs the mobility server912 in the network 910 (e.g., a media independent handover (MIH) serveris an example of mobility server) of the imminent HO via the interfaceIF2. The interface IF2 may be a new interface, or it may use an existinginterface such as a MIH protocol. The mobility server 912 may be locatedin the unicast service network 910, multicast service network 915, or ina different domain from the unicast or multicast networks. The mobilityserver 912 informs the OMA BCAST server 916 of the imminent HO andrequires service distribution in the downlink only network 925 via theinterface IF1. The interface IF1 is a new interface.

In a third example, the network 920 triggers a HO using the interfaceIF1. In this case the mobility server 912 may inform the OMA BCAST 916via the interface IF1. In a fourth example, the network 920 triggers aHO using the interface IF2, interface IF3, and interface IF4. On acondition that the interface IF1 does not exist, the mobility server 912may inform the mobility client 932 using the interface IF2. The mobilityclient 932 informs the OMA BCAST client 934 using the interface IF3 andthe OMA BCAST client 934 informs the OMA BCAST server 916 using theinterface IF4. In a fifth example, mobility is supported from the MAG940 or the LMA 935 in the distribution network.

A MAG (AR or PMIP) 940 and an LMA (Gateway) 935 may get informationabout a plurality of WTRUs 930 including the respective mobility andmulticast services information. The MAG 940 and the LMA 935 mayinterface with the multicast service network 915, or multicastdistribution network (downlink only) 925 to ensure the delivery of themulticast services when a WTRU 930 moves to the downlink only multicastnetwork 925.

The HO may occur from a downlink only multicast network 925 to abi-directional network 920. The network triggers the HO. The WTRU isinformed of the HO in the downlink control information. An imminent HOindication (i.e., information) is passed to the bi-directional networkvia interfaces in the network side, such as IF1. Alternatively, the WTRU930 triggers the HO. An uplink connection is required for the WTRU 930to inform the network of the imminent HO. The interfaces described abovefor the HO from a bi-directional network 920 to a downlink only network925 may be used to pass the HO information from the WTRU 930 to thenetwork.

The methods, examples, and embodiments described related to FIG. 9 formobility in hybrid networks do not assume any L3 or L2 mobility method,PMIP may or may not be used.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

Suitable processors include, by way of example, a general purposeprocessor, a special purpose processor, a conventional processor, adigital signal processor (DSP), a plurality of microprocessors, one ormore microprocessors in association with a DSP core, a controller, amicrocontroller, Application Specific Integrated Circuits (ASICs),Application Specific Standard Products (ASSPs); Field Programmable GateArrays (FPGAs) circuits, any other type of integrated circuit (IC),and/or a state machine.

A processor in association with software may be used to implement aradio frequency transceiver for use in a wireless transmit receive unit(WTRU), user equipment (UE), terminal, base station, Mobility ManagementEntity (MME) or Evolved Packet Core (EPC), or any host computer. TheWTRU may be used in conjunction with modules, implemented in hardwareand/or software including a Software Defined Radio (SDR), and othercomponents such as a camera, a video camera module, a videophone, aspeakerphone, a vibration device, a speaker, a microphone, a televisiontransceiver, a hands free headset, a keyboard, a Bluetooth® module, afrequency modulated (FM) radio unit, a Near Field Communication (NFC)Module, a liquid crystal display (LCD) display unit, an organiclight-emitting diode (OLED) display unit, a digital music player, amedia player, a video game player module, an Internet browser, and/orany Wireless Local Area Network (WLAN) or Ultra Wide Band (UWB) module.

1. A wireless transmit receive unit (WTRU) comprising: a receiverconfigured to receive a first Internet Protocol (IP) address that is forunicast services and a second IP address that is for multicast services;a processor configured to use the first IP address for the unicastservices and the second IP address for the multicast services; and atransmitter configured to transmit a router solicitation message to aserving mobile access gateway (MAG) triggering proxy binding update(PBU) messages that includes the second IP address.
 2. The WTRU as inclaim 1 wherein the transmitter is further configured to inform theserving MAG of imminent handover (HO).
 3. The WTRU as in claim 2 whereinthe WTRU is configured to move from the serving MAG to a next MAG via apredefined interface.
 4. The WTRU as in claim 1 wherein the processor isfurther configured to update policy profile of the WTRU according toIPv6 addresses of a local mobility anchors (LMAs).
 5. The WTRU as inclaim 1 wherein the WTRU uses multicast listener discovery/internetgroup management protocol (MLD/IGMP) messages to indicate to the servingMAG its request for multicast services.
 6. A method for a proxy mobileInternet Protocol (PMIP) supporting dedicated multicast local mobilityanchors (LMAs), the method comprising: a first LMA assigning a first setof Internet Protocol (IP) addresses to a wireless transmit receive unit(WTRU) dedicated for both unicast services and multicast services; andthe first LMA receiving a trigger from a mobile access gateway (MAG)indicating a proxy binging update (PBU) message.
 7. The method as inclaim 6 wherein the first LMA assigning the first set of IP addresses tothe WTRU for the unicast services and a second LMA assigning a secondset of IP addresses for the multicast services.
 8. The method as inclaim 7 wherein the first LMA receiving a trigger from a first MAGindicating a first PBU message from the first MAG, and the second LMAreceiving a trigger from a second MAG indicating a second PBU messagefrom the second MAG.
 9. The method as in claim 8 wherein on a conditionthat an existing PBU message is used, a new variable-length of multicastoptions field is added to the existing PBU message, and wherein amulticast flag is added in the PBU message.
 10. The method as in claim 7wherein the first LMA and the second LMA initiating establishment of anunicast tunnel and a multicast tunnel.
 11. The method as in claim 10wherein the multicast tunnel is unidirectional for downlink only trafficor bidirectional traffic.
 12. A method for a proxy mobile InternetProtocol (PMIP) supporting mobile access gateways (MAGs), the methodcomprising: a first MAG routing a first set of Internet Protocol (IP)addresses to a wireless transmit receive unit (WTRU) dedicated for bothunicast services and multicast services; the first MAG receiving arouter solicitation message from the WTRU; and the first MAG triggeringproxy binding update (PBU) message that includes multicast informationto a first local mobility anchor (LMA).
 13. The method as in claim 12wherein the first MAG routing a first set of IP addresses to the WTRUdedicated for the unicast services and the first MAG routing a secondset of IP addresses to the WTRU dedicated the multicast services. 14.The method as in claim 13 wherein the first MAG triggering an indicationof a first PBU message to a first LMA and a second PBU message to asecond LMA.
 15. The method as in claim 14 wherein the first MAGmaintaining a new PBU message list that includes binding of the WTRUwith the first LMA and the second LMA.
 16. The method as in claim 15wherein the first MAG discriminates between an unicast service trafficand a multicast service traffic to forward traffic to an appropriateinterface.
 17. The method as in claim 16 wherein the first MAGinitiating establishment of an unicast tunnel and a multicast tunnel.18. The method as in claim 17 wherein the multicast tunnel isunidirectional for downlink only traffic or bidirectional traffic.